Mohammad Rahnavardi

A systematic review on the safety and efficacy of percutaneous edge-to-edge mitral valve repair with the MitraClip system for high surgical risk candidates

Background MitraClip implantation has emerged as a viable option in high surgical risk patients with severe mitral regurgitation (MR). We performed the present systematic review to assess the safety and efficacy of the MitraClip system for high surgical risk candidates with severe organic and/or functional MR. Methods Six electronic databases were searched for original published studies from January 2000 to March 2013. Two reviewers independently appraised studies, using a standard form, and extracted data on methodology, quality criteria, and outcome measures. All data were extracted and tabulated from the relevant articles’ texts, tables, and figures and checked by another reviewer. Results Overall 111 publications were identified. After applying selection criteria and removing serial publications with accumulating number of patients or increased length of follow-up, 12 publications with the most complete dataset were included for quality appraisal and data extraction. All 12 studies were prospective observational studies. Immediate procedural success ranged from 72–100%; 30 day mortality ranged from 0–7.8%. There was a significant improvement in haemodynamic profile and functional status after implantation. One year survival ranged from 75–90%. No long term outcomes have been reported for high surgical risk patients. Conclusions MitraClip implantation is an option in managing selected high surgical risk patients with severe MR. The current evidence suggests that MitraClip can be implanted with reproducible safety and feasibility profile in this subgroup of patients. Further prospective trials with mid- to long-term follow-up are required.

Aortic valve-sparing operations in aortic root aneurysms: remodeling or reimplantation?

A best evidence topic was written according to a structured protocol. The question addressed was whether the reimplantation (David) technique or the remodeling (Yacoub) technique provides the optimum event free survival in patients with an aortic root aneurysm suitable for an aortic valve-sparing operation. In total, 392 papers were found using the reported search criteria, of which 14 papers provided the best evidence to answer the clinical question. A total of 1338 patients (Yacoub technique in 606 and David technique in 732) from 13 centres were included. In most series, cardiopulmonary bypass time and aortic cross-clamp time were longer for the David technique compared to the Yacoub technique. Early mortality was comparable between the two techniques (0-6.9% for the Yacoub technique and 0-6% for the David technique). There is a tendency for a higher freedom from significant long-term aortic insufficiency in the David group than the Yacoub group, which does not necessarily result in a higher reoperation rate in the Yacoub group. In the largest series reported, freedom from a moderate-to-severe aortic insufficiency at 12 years was 82.6 ± 6.2% in the Yacoub and 91.0 ± 3.8% in the David group (P=0.035). Freedom from reoperation at the same time point was 90.4 ± 4.7% in the Yacoub group and 97.4 ± 2.2% in the David group (P=0.09). In another series, freedom from reoperation at a follow-up time of about four years was 89 ± 4% in the Yacoub group and 98 ± 2% in the David group. Although some authors merely preferred the Yacoub technique for a bicuspid aortic valve, the accumulated evidence in the current review indicates comparable results for both techniques in a bicuspid aortic valve. Current evidence is in favour of the David rather than the Yacoub technique in pathologies such as Marfan syndrome, acute type A aortic dissection, and excessive annular dilatation that may impair aortic root integrity. Careful selection of patients for each technique and successful restoration of normal cusp geometry are the keys to success in aortic valve-sparing operations.

A systematic review of transapical aortic valve implantation

BACKGROUND Transcatheter aortic valve implantation (TAVI) through a transapical approach (TAAVI) for severe aortic stenosis becomes the procedure of choice in cases where patients have peripheral artery disease and unfeasible access due to excessive atherosclerotic disease of the iliofemoral vessels and aorta. The present systematic review aimed to assess the safety, success rate, clinical outcomes, hemodynamic outcomes, and survival benefits of TAAVI. METHODS Electronic searches were performed in 6 databases from January 2000 to February 2012. The primary end points included feasibility and safety. Other end points included echocardiographic findings, functional class improvement, and survival. RESULTS After applying the inclusion and exclusion criteria, 48 out of 154 shortlisted potentially relevant articles were selected for assessment. Of these, 26 studies from 24 centers including total number of 2,807 patients were included for appraisal and data extraction. The current evidence on TAAVI for aortic stenosis is limited to observational studies. Successful TAAVI implantation occurred in >90% of patients. On average, the procedure took between 64 to 154 minutes to complete. The incidence of major adverse events included 30-day mortality (4.7-20.8%); cerebrovascular accident (0-16.3%); major tachyarrhythmia (0-48.8%); bradyarrhythmia requiring permanent pacemaker insertion (0-18.7%); cardiac tamponade (0-11%); major bleeding (1-17%); myocardial infarction (0-6%); aortic dissection/rupture (0-5%); moderate to severe paravalvular leak (0.7-24%); cardiopulmonary bypass support (0-15%); conversion to surgery (0-9.5%); and valve-in-valve implantation (0.6-8%). Mean aortic valve area improved from 0.4-0.7 cm(2) before TAAVI to 1.4-2.1 cm(2) after TAAVI. The peak pressure gradient across the aortic valve decreased from >70 mmHg to <20 mmHg after TAAVI. One-year survival ranged from 49.3% to 82% and the 3-year survival was 58% in 2 series. CONCLUSIONS TAAVI appears to be feasible with a reasonable safety and efficacy portfolio. Randomised controlled trials are required to compare transapical vs. transfemoral TAVI when both techniques are equally feasible.

Intrathoracic application of a vacuum-assisted closure device in managing pleural space infection after lung resection: is it an option?

Empyema after lung resection is a challenging condition to manage and is associated with a high mortality. Intrathoracic application of a vacuum-assisted closure (VAC) device is recently introduced as an adjunct in the management of this condition. A best evidence topic was constructed to address whether this approach is effective in successful chest closure and reducing hospital stay. Twenty-three papers were found using the reported search, of which nine papers were identified that provided the best evidence to answer the question. All papers were retrospective and included a total of 69 patients treated with intrathoracic VAC. There was only one cohort study and the rest were either case series or case reports. In a cohort of 19 patients reported by Palmen et al. the average duration of an open window thoracostomy in a group of patients with VAC (n=11) was 39 ± 17 days and in those without VAC (n=8) was 933 ± 1422 days. Median length of VAC treatment was 22 days (range 6-66 days) in a series of 28 patients reported by Saadi et al. Some authors excluded patients with a bronchopleural fistula (BPF) from VAC treatment. However, Groetzner et al. have safely used VAC in patients with BPF after covering the bronchus stump with an intrathoracic muscle flap. The mediastinum and the bronchus can be covered using a polyvinyl-alcohol foam. Polyurethane foam is commonly used to fill the intrathoracic cavity up to the superficial wound. The suggested starting level of negative pressure is as low as -25 mmHg to -75 mmHg depending on the presence or absence of signs of mediastinal traction; this negative pressure can gradually be increased to -125 mmHg over time. The recommended interval between VAC changes is two to five days. Accumulated evidence in this article, although limited, suggests that VAC, as an adjunct to the standard treatment, can potentially alleviate the morbidity and decrease hospital stay in patients with empyema after lung resection. VAC can reduce inpatient length of treatment and can make the condition manageable in an outpatient setting. These results are yet to be proven by larger studies and clinical trials.